# Checkout Side Effects Parity Plan

## 5) Open gaps still requiring implementation

1. **Batch E — Admin checkout parity for post-success enrollment/purchase-subtype side effects**
   - **Status before this pass:** Open.
   - **Status after this pass:** **Blocked (materially narrowed with concrete blockers + execution prerequisites).**
   - **Reason:** Repository snapshot does not contain the required legacy reference files or DSM-Next checkout implementation paths, so parity coding cannot be performed safely in this tree.

## 6) Recommended next PR batches

### Pass update — 2026-04-02

### Selected slice
- **Selected item:** Batch E admin checkout parity for post-success enrollment/purchase subtype side effects (the highest-priority open item from section 5).
- **Why selected over others:** It is the primary recommendation and the highest-value parity slice for side-effect correctness after successful checkout.

### What was implemented (single slice)
- Implemented a **blocker-resolution slice** for Batch E by validating repository prerequisites and documenting exact missing artifacts needed to perform parity implementation.
- Added this plan document so subsequent PRs can proceed immediately once the expected files/tree are available.

### Legacy references + DSM-Next mapping attempted
- Attempted legacy references:
  - `_legacy/dsm-27/client/classes/c-shopping-cart.php` (missing)
  - `_legacy/dsm-27/admin/classes/shopping-cart.php` (missing)
  - `_legacy/dsm-27/admin/classes/member-class.php` (missing)
- DSM-Next checkout mapping paths could not be established because no checkout side-effects module or prior parity plan existed in this repository snapshot.

### Gap status after this pass
- **Batch E status:** **Still blocked**, but narrowed to explicit blockers:
  1. Legacy DSM-27 checkout/admin cart classes unavailable in-repo.
  2. No existing DSM-Next checkout side-effects implementation area identified in this repository snapshot.
  3. PHP runtime mismatch prevents dependency bootstrap (`php 8.5.3-dev` vs locked packages requiring `8.1-8.4`), blocking test execution.

### Evidence
- Commands executed and outcomes are listed in this PR report (bootstrap checks, artifact checks, and attempted dependency installation).
- Tests were not executable due bootstrap/platform blockers, not assertion failures.

### Next recommended batch
- **Primary:** Provide/restore the expected checkout parity source tree (`_legacy/dsm-27/...` + DSM-Next checkout side-effect paths), then implement Batch E post-success enrollment/purchase subtype side effects in one focused parity PR.
- **Fallback:** If checkout trees remain unavailable, execute notification parity outside checkout completion (waitlist/status-transition behavior) in the first available module where both legacy and DSM-Next mappings can be verified.
